Dark halo microphysics and massive black hole scaling relations in galaxies
We investigate the black hole (BH) scaling relation in galaxies using a model in which the galaxy halo and central BH are a self-gravitating sphere of dark matter (DM) with an isotropic, adiabatic equation of state. The equipotential where the escape velocity approaches the speed of light defines th...
| Main Authors: | , , |
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| Format: | Journal Article |
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Oxford University Press
2014
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| Online Access: | http://hdl.handle.net/20.500.11937/40376 |
| _version_ | 1848755854366474240 |
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| author | Saxton, C. Soria, Roberto Wu, K. |
| author_facet | Saxton, C. Soria, Roberto Wu, K. |
| author_sort | Saxton, C. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We investigate the black hole (BH) scaling relation in galaxies using a model in which the galaxy halo and central BH are a self-gravitating sphere of dark matter (DM) with an isotropic, adiabatic equation of state. The equipotential where the escape velocity approaches the speed of light defines the horizon of the BH. We find that the BH mass (m•) depends on the DM entropy, when the effective thermal degrees of freedom (F) are specified. Relations between BH and galaxy properties arise naturally, with the BH mass and DM velocity dispersion following m• ∝ σF/2 (for global mean density set by external cosmogony). Imposing observationally derived constraints on F provides insight into the microphysics of DM. Given that DM velocities and stellar velocities are comparable, the empirical correlation between m• and stellar velocity dispersions σ⋆ implies that 7 <~ F < 10. A link between m• and globular cluster properties also arises because the halo potential binds the globular cluster swarm at large radii. Interestingly, for F > 6 the dense dark envelope surrounding the BH approaches the mean density of the BH itself, while the outer halo can show a nearly uniform kpc-scale core resembling those observed in galaxies. |
| first_indexed | 2025-11-14T09:02:55Z |
| format | Journal Article |
| id | curtin-20.500.11937-40376 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:02:55Z |
| publishDate | 2014 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-403762017-09-13T13:38:56Z Dark halo microphysics and massive black hole scaling relations in galaxies Saxton, C. Soria, Roberto Wu, K. kinematics and dynamics – galaxies haloes – galaxies black hole physics structure – dark matter globular clusters: general - galaxies We investigate the black hole (BH) scaling relation in galaxies using a model in which the galaxy halo and central BH are a self-gravitating sphere of dark matter (DM) with an isotropic, adiabatic equation of state. The equipotential where the escape velocity approaches the speed of light defines the horizon of the BH. We find that the BH mass (m•) depends on the DM entropy, when the effective thermal degrees of freedom (F) are specified. Relations between BH and galaxy properties arise naturally, with the BH mass and DM velocity dispersion following m• ∝ σF/2 (for global mean density set by external cosmogony). Imposing observationally derived constraints on F provides insight into the microphysics of DM. Given that DM velocities and stellar velocities are comparable, the empirical correlation between m• and stellar velocity dispersions σ⋆ implies that 7 <~ F < 10. A link between m• and globular cluster properties also arises because the halo potential binds the globular cluster swarm at large radii. Interestingly, for F > 6 the dense dark envelope surrounding the BH approaches the mean density of the BH itself, while the outer halo can show a nearly uniform kpc-scale core resembling those observed in galaxies. 2014 Journal Article http://hdl.handle.net/20.500.11937/40376 10.1093/mnras/stu1984 Oxford University Press fulltext |
| spellingShingle | kinematics and dynamics – galaxies haloes – galaxies black hole physics structure – dark matter globular clusters: general - galaxies Saxton, C. Soria, Roberto Wu, K. Dark halo microphysics and massive black hole scaling relations in galaxies |
| title | Dark halo microphysics and massive black hole scaling relations in galaxies |
| title_full | Dark halo microphysics and massive black hole scaling relations in galaxies |
| title_fullStr | Dark halo microphysics and massive black hole scaling relations in galaxies |
| title_full_unstemmed | Dark halo microphysics and massive black hole scaling relations in galaxies |
| title_short | Dark halo microphysics and massive black hole scaling relations in galaxies |
| title_sort | dark halo microphysics and massive black hole scaling relations in galaxies |
| topic | kinematics and dynamics – galaxies haloes – galaxies black hole physics structure – dark matter globular clusters: general - galaxies |
| url | http://hdl.handle.net/20.500.11937/40376 |